Characterize the oncogenic herpesviruses, Herpesvirus saimiri, and Herpesvirus ateles, and determine their pathogenicity in primates and other animal species. Determine if H. saimiri attenuated by passage in vitro can be employed to prevent the malignant lymphoma induced by the parent virus in the susceptible animal species. Determine if several new herpesvirus isolates obtained from South American monkeys have oncogenic properties in non-human primates, or other species.